Glycolic acid and niacinamide are two of the most popular active ingredients in skincare products right now. And it’s no wonder, since they promise to make your skin look smoother, brighter and more even (among many other benefits). So why not incorporate both of them into your routine?
But that’s where things can get tricky. Should you mix them together, or look for both in one product? Is it better to apply them in layers? Which one goes on first? And will one inactivate the other?
If you’ve been pondering these questions, this tutorial is for you. Keep reading to learn what glycolic acid and niacinamide can do for your skin, why they’re better together, how to use both in one routine, and the best products to try.
What Does Glycolic Acid Do for Your Skin?
Glycolic acid is the most common chemical exfoliant, as well as one of the strongest. That’s because it is the alpha-hydroxy acid (AHA) with the smallest molecule size, so it easily penetrates the skin. Here are the main things it can do:
- Exfoliates dead skin: It breaks down the “glue” that holds dead skin cells together in the stratum corneum (the uppermost layer of our skin). This allows them to be sloughed off, revealing the fresh new skin underneath.
- Smooths texture: A study found that as little as 5% produced a significant improvement in general skin texture after three months.
- Brightens and fades pigmentation: All hydroxy acids help with brightening by removing the old dead skin cells that contribute to dull-looking skin. Glycolic acid has also been shown to improve sun-induced discolourations and sallowness.
- Thickens and firms: By increasing collagen production, glycolic acid can help skin to feel thicker and firmer. One study, using a 15% concentration, found that it increased epidermal thickness by 27% after six months.
- Improves hydration: As a humectant, glycolic acid draws moisture into the skin. It also increases the skin’s hyaluronic acid content.
What Does Niacinamide Do for Your Skin?
Niacinamide is the active form of vitamin B3, and works by giving our skin cells the energy to carry out their functions. That makes it suitable for treating a wide range of skin concerns, with virtually no side effects. Here’s what it does:
- Brightens and fades pigmentation: In addition to treating melasma, it has been shown to significantly decrease hyperpigmentation. One study found that, in combination with vitamins E and B5, it significantly improved skin tone evenness in only six weeks.
- Strengthens the skin barrier: It improves the function of the skin barrier by reducing TEWL (transepidermal water loss) and increasing levels of ceramides and other barrier components. This leads to a thicker, more resilient stratum corneum that retains hydration and is resistant to damage.
- Reduces wrinkles: Multiple studies demonstrated that niacinamide helps with fine lines and wrinkles. For example, a concentration of 5% significantly reduced wrinkles after 12 weeks, while 4% improved eye-area wrinkles in just eight weeks.
- Smooths texture: Both 4% and 5% also produce significant improvements in skin texture.
- Reduces oil and clears acne: It can help to control excess oil by lowering the amount and rate of sebum excreted. For mild to moderate acne, two studies have found niacinamide to be comparable in efficacy to clindamycin, a topical antibiotic.
- Calms redness: Last but not least, it can also help with red, blotchy skin and even rosacea.
Should You Use Both Glycolic Acid and Niacinamide?
If glycolic acid is your chemical exfoliant of choice, then you should definitely consider niacinamide, too. While each ingredient can produce visible improvements on its own, you’ll get the best results from incorporating the two of them into your skincare routine.
This is because glycolic acid is notoriously irritating, thanks to its low molecular weight. For many people, it can cause dry, flaky skin and even redness, stinging and inflammation, especially when first starting treatment. This is expected and usually improves as your skin gets used to the acid. However, it’s also important to choose an appropriate strength of glycolic acid, and use it only as often as your skin can tolerate.
Niacinamide can help to minimize these potential side effects by making your skin barrier stronger and thicker. It won’t be as vulnerable to irritation, and will become better at holding onto moisture. It will also help to calm down any redness.
Best of all, by using these two ingredients, you’ll be getting double the benefits in terms of smoothing, brightening, fading pigmentation, firming and reducing wrinkles. What’s not to love about that?!
Can You Mix Glycolic Acid and Niacinamide?
What happens if you mix glycolic acid with niacinamide?
Your Acid Won’t Be Effective
Combining these ingredients is going to make your acid less effective. In order to do their jobs, hydroxy acids are formulated at a certain pH level. For glycolic acid, it’s typically between pH 3.0 and 4.0.
But niacinamide has a much higher pH, around 6.0. So if you mix the two ingredients together, the niacinamide is going to raise the pH of the glycolic acid, so it will no longer be acidic.
That means you won’t get much (if any) benefit from using the acid. One study compared the absorption of AHAs at pH 3.0 and 7.0, and found that the higher the pH, the less the skin absorbs—and the less activity the AHAs have on the skin.
You Can Trigger a “Niacin Flush”
Another problem with mixing glycolic acid and niacinamide is that it can cause redness and flushing. This is from the glycolic acid lowering the pH of the niacinamide below its optimal range.
While niacinamide is meant to be around pH 6.0, acidic conditions can trigger its conversion into niacin, another form of vitamin B3.
If you’ve ever taken an oral niacin supplement, then you may have experienced the infamous “niacin flush.” Although harmless, it temporarily makes your skin red, hot and flushed (due to the release of prostaglandin D2).
Now, imagine the same thing, but concentrated on your face. I’ve tested this out myself, and it's no joke. I looked like a lobster, felt very uncomfortable, and the effect lasted one to two hours. Makeup can’t even cover it up!
I believe this is why some people think they can’t tolerate niacinamide, even though it is one of the gentlest and most non-toxic ingredients in skincare. If you’re incorrectly combining it with an acid, it can appear to cause irritation, even though it’s just this “niacin flush.”
How to Use Glycolic Acid and Niacinamide Together
To get the best results, and to avoid the “niacin flush,” you’ve got three options:
1. Apply Them in a Single Product
While it’s not advisable to play chemist and mix two separate products, you can use a pre-made product that includes both glycolic acid and niacinamide together. This is because it will be expertly formulated to remain stable and effective at a certain pH level.
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The trade-off for the convenience of an all-in-one product is that it won’t be as potent. Since glycolic acid and niacinamide don’t play well together, a combination formula will not contain the high concentrations that you can get when using them individually, nor will it be at the optimal pH.
If this is a compromise that you’re willing to make, try one of the following:
- COSRX AHA 7 Whitehead Power Liquid contains 7% glycolic acid and 2% niacinamide, with a pH between 4.0 and 5.0.
- Versed Weekend Glow Daily Brightening Solution features 3% glycolic acid and an estimated 0.5-2% niacinamide (based on the order of the ingredients list). Its pH is between 5.0 and 6.0.
- Rose Ingleton MD Blemish Control Booster is a gentle exfoliating serum. While their percentages aren’t disclosed, niacinamide is the second ingredient and glycolic acid is the third.
- Moon Juice Acid Potion Resurfacing Exfoliator has a 25% acid complex (which primarily consists of glycolic), and niacinamide is the fifth ingredient.
2. Apply Them at Different Times of Day
If you’ve decided that two separate products are the way to go, the easiest way to use them is at different times of day. What you use when is totally up to you, but my recommendation is to apply your niacinamide in the morning and your glycolic acid at night.
First of all, this will save time if your mornings are rushed. Since niacinamide is non-acidic, you can put it under products with a similar pH—like your hydrating serum, moisturizer and/or sunscreen—without having to wait in between layers.
Glycolic acid, on the other hand, needs to be separated from higher-pH products by about 30 minutes, to give it time to work at its acidic pH. Most of us have more time to incorporate this waiting period when we’re doing our nighttime skincare routines.
Another reason to use your glycolic acid at night is because it can make your skin more sun-sensitive. However, if you do decide to use it in the morning, be sure to follow with a good mineral sunscreen, about 30 minutes after the acid.
3. Apply Them on Alternate Mornings or Nights
Another option is to apply your glycolic acid and niacinamide on alternate mornings or nights. So, one night you could apply your glycolic acid after cleansing, and the next night, you could use your niacinamide. Or, this could happen in the mornings, if you prefer.
Again, the one caveat here is that you need to be mindful of pH levels if you plan to layer other skincare products on top. My general rule is that any products that are more than about 1.0 to 2.0 apart need to be separated by a 30-minute waiting period. Always apply your products in order of lowest to highest pH.
4. Apply Them 30 Minutes Apart
For those of us with complicated routines, who like using all the skincare, there’s one more way you can use these two ingredients. You can actually layer your glycolic acid and niacinamide together, at the same time of day—just 30 minutes apart.
When layering products, start with the one that has the lowest pH first. This will be your glycolic acid, which you’ll apply straight after cleansing. Leave it on your skin to do its thing for a good 30 minutes.
The 30 minutes will give it enough time to perform its functions, and then allows your skin’s pH to return from an acidic state back to normal (about pH 5.5). When the time is up, you can proceed with the niacinamide, without having to worry about changing its pH and triggering a flush. Finish with your hydrators and/or sunscreen.
You can do this as often as once or twice a day, depending on how well your skin tolerates the glycolic acid.
The Best Glycolic Acids to Try
Paula’s Choice Skin Perfecting 8% AHA Gel Exfoliant
Paula’s Choice Skin Perfecting 8% AHA Gel Exfoliant features 8% glycolic acid in a lightweight gel base, with a pH range of 3.5-3.9.
The Inkey List Glycolic Acid Toner
The Inkey List Glycolic Acid Toner boasts 10% of the active ingredient, along with 5% witch hazel water to help with oil control.
Sanitas GlycoSolution 15%
Sanitas GlycoSolution 15% is an intensive exfoliant with a high 15% concentration of the acid and sodium PCA to hydrate.
Dr Loretta Micro Peel Peptide Pads
Dr Loretta Micro Peel Peptide Pads let you swipe on 10% glycolic acid, along with plant peptides, probiotics and algae extract.
The Ordinary Glycolic Acid 7% Toning Solution
The Ordinary Glycolic Acid 7% Toning Solution combines 7% of the active ingredient with an array of soothing botanicals. It has a pH between 3.5 and 3.7.
IT Cosmetics Bye Bye Pores Glycolic Acid Serum
IT Cosmetics Bye Bye Pores Glycolic Acid Serum has 10% of the acid in a simple, fragrance-free formula. (There is some alcohol in here, but it’s acting as a penetration enhancer.)
COSRX AHA 7 Whitehead Power Liquid
COSRX AHA 7 Whitehead Power Liquid is a light, liquid gel infused with 7% glycolic acid, 2% niacinamide and hyaluronic acid. It has a pH of 4.0-5.0.
Malin+Goetz Resurfacing Glycolic Pads
Malin+Goetz Resurfacing Glycolic Pads are soaked in just three ingredients, including 10% glycolic acid.
The Best Niacinamide Serums to Try
Paula’s Choice 10% Niacinamide Booster
Paula’s Choice 10% Niacinamide Booster contains 10% of the active and has a watery, fast-absorbing texture that is perfect for layering.
Kristina Holey + Marie Veronique Soothing B3 Serum
Kristina Holey + Marie Veronique Soothing B3 Serum is a sensitive skin-friendly formula made with 10% niacinamide, all-clean ingredients, and no fragrance or essential oils.
Allies of Skin Prebiotics & Niacinamide Pore Refining Booster
Allies of Skin Prebiotics & Niacinamide Pore Refining Booster is a weightless serum with 10% niacinamide plus prebiotics, probiotics, Centella Asiatica and hyaluronic acid.
The Inkey List Niacinamide
The Inkey List Niacinamide not only has 10% of the star ingredient, it’s also infused with 1% hyaluronic acid for extra hydrating benefits.
Sobel Skin Rx 15% Niacinamide Gel Serum
Sobel Skin Rx 15% Niacinamide Gel Serum is loaded with one of the highest concentrations of niacinamide, at 15%. It also contains soothing allantoin and cucumber.
Good Molecules Niacinamide Serum
Good Molecules Niacinamide Serum is a non-sticky, water-based serum with 10% niacinamide.
The Ordinary Niacinamide 10% + Zinc 1%
The Ordinary Niacinamide 10% + Zinc 1% is a gel-like serum with 10% of the active and an additional 1% zinc to help balance excess oil.
Glossier Super Pure Niacinamide + Zinc Serum
Glossier Super Pure Niacinamide + Zinc Serum smooths, clarifies and lightly hydrates with 5% niacinamide and zinc PCA.
Conclusion + Further Reading
If you’ve ever wondered whether you can use both glycolic acid and niacinamide in one skincare routine, rest assured—you definitely can.
Although there are a few glycolic acid-based exfoliants out there that also contain niacinamide (like COSRX and Versed), I suggest investing in two separate treatments if you want to see the best results.
Glycolic acid is the most effective when it’s formulated at a low pH (around 3.0 to 4.0), and in a concentration of at least 8%. Most of the studies on niacinamide used concentrations of 4-5% to obtain significant improvements in texture, pigmentation, fine lines and more.
The key is to make sure you use them at the right time, in the right order, to keep their pH levels as intended—and to avoid the dreaded red flush!
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- Thibault, P. K., Wlodarczyk, J. & Wenck, A. (1998). A double-blind randomized clinical trial on the effectiveness of a daily glycolic acid 5% formulation in the treatment of photoaging. Dermatologic Surgery. 1998 May; 24(5): 573-7; discussion 577-8.
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- Bissett, D. L., Miyamoto, K., Sun, P, Li, J. & Berge, C. A. (2004). Topical niacinamide reduces yellowing, wrinkling, red blotchiness, and hyperpigmented spots in aging facial skin. International Journal of Cosmetic Science. 2004 Oct; 26(5): 231-8.
- Kawada, Akira, Konishi, Natsuko, Oiso, Naoki, Kawara, Shigeru & Date, Akira. (2008). Evaluation of anti-wrinkle effects of a novel cosmetic containing niacinamide. The Journal of Dermatology. 2008 Oct; 35(10):637-42.
- Draelos, Zoe Diana, Matsubara, Akira & Smiles, Kenneth. (2006). The effect of 2% niacinamide on facial sebum production. Journal of Cosmetic and Laser Therapy. 2006 Jun; 8(2): 96-101.
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- Kraeling, Margaret & Bronaugh, Robert L. (1997). In vitro percutaneous absorption of alpha hydroxy acids in human skin. Journal of the Society of Cosmetic Chemists. 1997 Jul; 48, 187-197.
- Finholt, Per & Higuchi, Takeru. (1962). Rate studies on the hydrolysis of niacinamide. Journal of Pharmaceutical Sciences. 1962 Jul.
- Morrow, J. D., Awad, J. A., Oates, J. A. & Roberts, L. J. (1992). Identification of skin as a major site of prostaglandin D2 release following oral administration of niacin in humans. Journal of Investigative Dermatology. 1992 May; 98(5): 812-5.
- Kornhauser, Andrija, Wei, Rong-Rong, Yamaguchi, Yuji, Coelho, Sergio G., Kaidbey, Kays, Barton, Curtis, Takahashi, Kaoruko, Janusz, Z., Miller, Sharon A. & Hearing, Vincent J. (2009). The Effects of Topically Applied Glycolic Acid and Salicylic Acid on Ultraviolet Radiation-Induced Erythema, DNA Damage and Sunburn Cell Formation in Human Skin. Journal of Dermatological Science. 2009 Jul; 55(1): 10–17.
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